As Black you possibly need to memorize some critical lines to avoid disaster. As White you can easily get out of the books with a playable middlegame if you avoid sharp openings and don't mind playing a theoretical equal position.
You just need a photographic memory
You need to play Chess960!
No more memorizing enless opening repetoires. Instead, the players begin thinking for themselves on Move 1!
If you want to use your memory in chess, memorize key endgame positions and how to win them.
A good memory is of course an advantage in chess, but it's not necessary. Chess rewards players who can visualize the board well. Work on your visualization skills by analysing positions 5 moves (10 ply) deep then work out exactly where each piece is.
Very few people have truly eidetic memories. Don't be intimidated by your opponent.
If you want the "big picture" on Opening Theory, read GM Johan Hellsten, Mastering Opening Strategy, (2012).
It's simple, sort of. 
And you will quickly realize that his appendix suggestions for building an opening repetoire is gearing toward very serious players only. That is, people willing to devote massive amounts of time to chess.
IF that shoe fits, wear it. Otherwise, the OP should stop whining.
Thanks!
I already visited amazon to take a look there. I'm impressed with the game index! The chapters make sense, but I'm wondering how much is different from other books on how to develop. Is it just newer examples, or does Hellsten offer different insights?
Hellsten's new book on "Opening Strategy" is largely a 10-15 ply deep book of positions, from GM games. He explains the theme, and shows how it's played out.
Then he follows with lots of exercises of the type -- "find the next move and gives me your short plan."
Basically it's the same format as his (other book) Mastering Chess Strategy (2010). Which is 500 pages long, including about 400 short exercises, of roughly 10-15 deep.
His analysis is always (much) deeper than I ever calculate. But everything is broken down in manageable pieces. That's what I prefer, and similar to how themes are presented in Michael Stean, Simple Chess (2003).
Sometimes Hellsten is a bit dense (for me), but his analysis is always crisp and to the point. Good book.
P.S., but there is no "whole game" analysis. If that's what you prefer, @SmyslovFan, it might not be the book for you.
Stop trying to bring this lame thread back to life. It's braindead.
You demonstrate (again) that you don't have the foggiest idea how to study openings -- either specific openings or generic opening strategy.
Maybe it's time for you to start playing "Hang Man" or tic-tac-toe, instead?
I still maintain that a person who spends time getting to know each opening and its consequences in several common possible variations can save a lot of time in a game instead of trying to analyze each opening and subsequent moves anew in real time and in the fresh state. And time is very important in chess.
Also if you have seen games where the "underdog " beats a superior player. It is often because the less experienced player uses unpredictable responses and moves that represent the more unusual variations of a certain sequence that the expert is less familiar with.
I still maintain that a person who spends time getting to know each opening and its consequences in several common possible variations can save a lot of time(??) in a game instead of trying to analyze each opening and subsequent moves anew in real time and in the fresh state. And time is very important in chess.
Also if you have seen games where the "underdog " beats a superior player. It is often because the less experienced player uses unpredictable responses and moves that represent the more unusual variations of a certain sequence that the expert is less familiar with (??).
Duh? The above -- Makes No Sense. Q.E.D.
Indeed, I will happily leave you (and your self-referential thread) to your own muddled devices.
PLEASE, try re-reading what others have already told you. (excluding my comments, of course).
The answers that you seek, Grasshopper, lay within. 
Have a Nice Day.
what is not clear about " saves a lot of time " ? If you already know the few ways a certain opening can progress then you dont need to analyze it each time you play it.
If you show me where I am wrong I will be the first to admit it but sorry, I dont see it.
About the "less familiar sequence"
Here is a link that is interesting:
http://www.youtube.com/watch?v=FOA1ycmyeak
This is a fast game and afterwards an interview with G. Kasparov and N. Short. Check what Nigel Short says at 11:10 , (11 minutes 10 seconds) in this video. He says that he beat Kasparov because he used a different strategy, perhaps less familiar and unexpected. This was towards the end game but can maybe be used also in middle game or even opening.
The point being neutralizing the advantage of experience and years of studying games to just matching pure wits and instant strategy with unfamiliar positions.
and sorry, certainly did not mean to offend. 

Maybe success in chess is like success in life. Its in the eye of the person themselves. For one person it may be a major success and accomplishment to go from 1200 to 1400, for another from 1800 to 2100.